An accepted procedure for packing a shipping container with a plurality of like articles or product, such as cans, cartons, or packages, is to accumulate and stack the product before it is loaded into the container. A particularly efficient method for loading a standard corrugated shipping container is to insert a stack of accumulated product through its open bottom. An apparatus for carrying out this bottom loading method is shown in U.S. Pat. No. 3,605,377.
To increase the production rate and efficiency of such carton loading apparatus, it is necessary to solve the problem of stacking and accumulating the product in a precise manner and at a high rate. Moreover, it is essential that the stacking operation be accomplished automatically and yet without damaging the product. Usually, the product is supplied in a constantly moving stream or line from a conveyor belt and from this line the individual product elements must be maneuvered and stacked into the desired accumulation. In prior apparatus for accumulating or stacking articles, they were first moved from the conveyor to an intermediate station and then pushed onto a vertically movable loading platform. After each tier of articles was positioned onto the loading platform, it was lowered to receive the next tier of articles. Such an arrangement was functional but relatively slow and a serious disadvantage where a high output rate is required. Previous attempts to solve this problem resulted in relatively complicated and impractical machines adaptable for use with only certain specialized products, such as the apparatus for stacking bricks, described in U.S. Pat. No. 4,068,766.
It is, therefore, a general object of the present invention to provide an improved apparatus for accumulating and stacking a plurality of product for subsequent loading into a shipping container; to provide an accumulating and stacking apparatus that will operate automatically at a relatively high cycling rate; and to provide a product stacking apparatus that is particularly adaptable for operation with a bottom carton loading machine.